1. Field of the Invention
The present invention relates to a sheet cutter for cutting an object to be cut such as a sheet, and more particularly an improvement of a cutting mechanism that enables perfect cutting with a simple structure.
2. Description of the Related Art
In an ordinary device for cutting a sheet or the like, a sheet or sheets are set on a placing table mounted on an installation plane such as a table to be maintained thereon by a press mechanism, and are cut by a cutting blade.
A cutting mechanism including a cutting blade of a short sword or knife shape pivotally and swingably supported at one end thereof, in which a sheet placed on a placing table is cut by an action of pressing down the cutting blade from an initial upper position, has been known in the art. For example, Japanese Patent No. 4783912 discloses a cutting machine, in which a cutter blade rotatably supported at one end thereof is operated downward to cut sheets which are placed on a flat surface of a base and retained thereon by a paper presser, along a side edge of the base.
Another cutting mechanism including a circular blade or a rectangular blade of a chisel shape, in which the blade travels along a cutting line to cut a sheet or sheets on a placing table, has been known in the art. For example, Japanese patent application publication No. 07-000651 describes a sheet cutter, in which a base is placed on a sheet to be cut, and a blade mounted on the base to project downward through a through groove formed in the base is moved along a rail to cut the sheet.
Further, in order to maintain sheets on a placing table, a cutting mechanism which is provided with a cutting blade that is moved downward to cut the sheets, and a pressing part that is operated to press the sheets on the placing table interlocking with a cutting action of the cutting blade has been known in the art.
In the above conventional technology, an object to be cut such as a sheet is pressed and retained on a placing plane by an initial action of a cutting operation, or by a pressing mechanism which is operated separately from and prior to a cutting operation by a cutter.
However, it is not always easy for an unskilled user to perform both an action of pressing sheets and an action of cutting sheets at different timings, and there is a risk of injuring the user's hand or fingers during the cutting operation by mistake. For example, when moving a cutting blade in a cutting direction with one hand while setting the sheets on the placing table with the other hand, it may cause injury of the other hand or its fingers, if adequate attention is not paid.